Western Flower Thrips

Western Flower Thrips in Greenhouses- from Dr. Stephen Franks, NCSU Dept of Entomology

Thrips are a constant problem for growers. Not just this particular week, but all the time. Western flower thrips, Frankliniella occidentalis, is the most important and damaging thrips of greenhouses and has been called the most damaging greenhouse pest in the world. This is true of greenhouse-grown food and ornamental crops. Nearly all floriculture crops are susceptible to thrips damage. Western flower thrips reproduce rapidly and are difficult to manage because they live in the cracks and crevices of flower heads and foliage. Thus they are difficult to contact with insecticides. Western flower thrips also develop insecticide resistance rapidly so it is important to emphasize chemical rotation and to have a resistance management plan. Sanitation is also very important in managing thrips. Because they can feed and reproduce on hundreds of plant species, weeds in and around a greenhouse will provide a constant supply of thrips even if the crop is sprayed. Western flower thrips pupate in soil, so clean up spilled potting soil and other debris to deny them this vital part of their lifecycle. More information and chemical recommendations can be found in the newly-revised Ornamentals and Turf Insect Note No. 72 at Western Flower Thrips

For more information contact your local Cooperative Extension Center and ask for the Commercial Horticulture Agent.